The present disclosure relates to an image reading device applied to a scanning device, copying machine, a multifunction peripheral or the like and configured to optically read a document, and an image forming apparatus.
Generally, an image reading device applied to a scanning device, copying machine, a multifunction peripheral or the like includes a document platen, a movable part, a motor and others. The document platen is made of a glass and formed in a rectangular flat board-like shape. The movable part is located below the document platen and configured to move in a direction (a sub scanning direction) along a long side of the document platen. The motor moves the movable part. The image reading device further includes a linear-formed light source and an imaging part. The linear-formed light source extends in another direction (a main scanning direction) along a short side of the document platen and configured to irradiate a document with scanning light. The imaging part receives the scanning light irradiated from the linear-formed light source and reflected by the document and generates image data corresponding to the received scanning light. The linear-formed light source is, for example, provided in the movable part and configured to irradiate the document placed on a top face of the document platen with the scanning light while moving in the sub scanning direction together with the movable part.
On the other hand, there are some image reading devices that include a lock sensor detecting whether or not the movable part is locked at a locking position by a locking mechanism. In such an image reading device, the lock sensor can detect an unmovable state of the movable part caused by locking it at the locking position by the locking mechanism. However, as a method of detecting the unmovable state of the movable part due to other cause, the image reading device generally applies a method of driving the motor for a predetermined time or more.